Study On The Effects Of Mineralizer And Additives On Properties Of Silicon Oxide Ceramic Core

The preparation process of ceramic core is one of the key technologies for preparing hollow blade of nickel based superalloy,It can be used to form complex pores and air passage inside the blade.At present,the most mature development of the country is the silica based ceramic core.To judge whether the performance of a ceramic core meets the requirements,it mainly deals with the bending strength,shrinkage ratio,porosity,and high temperature deflection.This topic mainly aims at the high temperature deflection of the ceramic core,and takes into account other aspects of performance,so that it can achieve a good comprehensive performance.In this study,the influence of different mineralizer,nano silica and zirconia on the performance of ceramic core is studied,and a good formula for preparing ceramic core is selected.The results show that the flexural strength and shrinkage ratio of the ceramic core with zircon powder as mineralizer are higher than those with mullite as mineralizer,while the samples with zircon powder as mineralizer have higher deflection at high temperature.Therefore,relatively speaking,the core performance of this type of core is better than that of the core with mullite as mineralizer.With the increase of nano silica(0 to 1%),the flexural strength of ceramic core increases gradually,the deflection of high temperature is smaller and smaller,and the sintering shrinkage is lower than that of nano silica.Therefore,when the content of nano silica is 1%,the core has the best comprehensive performance.With the increase of the content of zirconia(0 to 1%),the flexural strength of the ceramic core gradually increased,the high temperature deflection first increased,then decreased,and the burning shrinkage rate of the ceramic core was smaller than that of the zirconia free sample.Therefore,when the content of zirconium oxide is 1%,the comprehensive performance of the sample is the best.The objective of this research is to reduce the deflection of high temperature ceramic core,therefore,under the premise of ensuring the performance,choose 1%zirconium oxide nano silicon oxide and 1% as additive,the ceramic core 25% zircon powder as mineralizer is appropriate.